Annealing



Jam 24, 1939. A c. f TOLL v 2,144,904

` ANNEALING Filed Feb; 21, 1935 Patented Jan. 24, 1939 UNITED STATES PATENT OFFICE &144304 ANNEALING Application February 21, 1935, Seriai No. 7,618

1 Claim.

This invention relates in general to annealing. and is particularly concerned with box or pot annealing, one of the objects being to pot anneal high carbon steel, wire or strip. Other objects may be inferred.-

According to the invention, wire is loaded onto an annealing pot and supported in spaced relationship respecting the entire inside of thelatter during the annealing operation. This is done to permit the gases enclosed in the pot to circulate more freely. Granular or porous carbonaceous material, such as charcoal, is then arranged in` the pot sc that the gases may contact therewith during the annealing operation. All leaks between the inside and outside of the pot are then sealed with carbonaceous material, and a cover is provided so as to protect it-from the furnace atmosphere.

Annealing is conducted in the usuai manner 20 after the above acts have been performed. No appreciable decarburization of the charge will occur during this operation.

In the accompanying drawing, Figure 1 is a cross-section and Figure 2 a vertical section of an annealing pot that is expressly designed to ac'- commodate the practice which has been described.

This drawing shows an annealing pot I that is distinguished by being of somewhat larger di- 30 ameter than the usual pot and by having a top 4 providing at least two closure seats 2 and 3. Also,

the pot has an apertured internal shell 4 spaced from its outside, this shell being adapted to position the required granular or porous material 35 between it and the inside of the walls of the pot.

This shell is provided with outwardly extending fianges 5, which serve to maintain the shell and pot in concentric reiation, and apertures Sa, so that at least a portion of the gases 'enclosed by 6 the pot can circulate through and mingle with the carbonaceous material contained therein. The diameter of this shell is such as to permit loading of coils of wire 6.

. The coils of wire 6 are carried by a work sup- 5 port 'I of the character described and claimed by my Patent No. 1,933A61. 'This support positions the coils of wire in spaced relationship respecting the entire inside of the pot i, whereby the gases enclosed by the latter may circulate more f'eely.

A first ciosure 8 is iaid on the lower closure 5 seat 2 and a second closure 9 is laid on the upper scat 3. Both of these closures may be concentrically apertured `so as to permit the insertion of a thermocouple o into the pot.` It is to be noted that both the closures 8 and 9 are so con- 1 structed and arranged that both may be sealed With granularmaterial.

In following the method described, the material positioned by theshell 4 may be any granular or porous material that is high in carbon. The granular material which seals the closure 8 should' also be of a carbonaceous character. The

upper closure 9 may be sealed with a metallic oxide or any suitable refractory, whereby it functions to protect the carbonaceous material sealing the lower closure 8 from the furnace' atmosphere. i

I claim:

A method of pot annealing articles. including arranging articles to be annealed in substantiaily annular formation in a container in spaced relation from the walls and ends of said container to provide gas passages interiorly and exteriorly of said articles, disposing carbonaceous material within said passage exteriorly of said articles, scaling said container, applying heat to said container -to anneal said. articles, said passage exteriorly of said articles establishing a higher temperature zone and said passage interiorly of said articles establishing a lower temperature zone, and circulating the atmosphere gases enclosed by said container upwardly through said higher temperature' zone by the inherent expansion thereof, thereby carburizing said gases within said higher temperature zone, and circuiating 40 said gases downwardly through said lower temperature zone by the relative contraction of said gases, thereby exposing said articles to the ascending carburized gases within said container.

CARL J. TOLL. 

